From bb937155ec5c035865256a86e3659f9aa83fc5ba Mon Sep 17 00:00:00 2001
From: Colin McQuillan <m.niloc@googlemail.com>
Date: Sat, 15 Aug 2009 11:22:55 +0000
Subject: Add a function that can apply an order 2 rational transfer function
 in-place. This function will be used in the upcoming AMR-NB floating point
 decoder for high-pass filtering.

Patch by Colin McQuillan ( m.niloc googlemail com )

Originally committed as revision 19649 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/acelp_filters.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

(limited to 'libavcodec/acelp_filters.h')

diff --git a/libavcodec/acelp_filters.h b/libavcodec/acelp_filters.h
index b7f6a3abcb..2cbe9bb17d 100644
--- a/libavcodec/acelp_filters.h
+++ b/libavcodec/acelp_filters.h
@@ -81,4 +81,20 @@ void ff_acelp_interpolate(int16_t* out, const int16_t* in,
 void ff_acelp_high_pass_filter(int16_t* out, int hpf_f[2],
                                const int16_t* in, int length);
 
+/**
+ * Apply an order 2 rational transfer function in-place.
+ *
+ * @param samples [in/out]
+ * @param zero_coeffs z^-1 and z^-2 coefficients of the numerator
+ * @param pole_coeffs z^-1 and z^-2 coefficients of the denominator
+ * @param gain scale factor for final output
+ * @param mem intermediate values used by filter (should be 0 initially)
+ * @param n number of samples
+ */
+void ff_acelp_apply_order_2_transfer_function(float *samples,
+                                              const float zero_coeffs[2],
+                                              const float pole_coeffs[2],
+                                              float gain,
+                                              float mem[2], int n);
+
 #endif /* AVCODEC_ACELP_FILTERS_H */
-- 
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